Field of the Invention
The invention relates to a contact connection of shielded data lines to a board and to a method for contacting a number of shielded data lines with a board.
In the sphere of data transmission, for example in computer networks, for the data transmission use is made of data cables in which typically a plurality of data lines is combined in a common cable sheath. In the case of high-speed data transmissions, the data lines used are in each case shielded pairs of insulated wires, wherein the two insulated wires in particular run parallel to each other or alternatively are twisted with each other. A respective insulated wire consists here of the actual conductor, for example a solid conductor wire or else a stranded wire, which is surrounded in each case by insulation. The pair of insulated wires of a respective data line is surrounded by a (pair) shielding. The data cables typically have a multiplicity of such shielded pairs of insulated wires which are surrounded by a common cable sheath.
Data cables of this type are connected in pre-manufactured form to connectors. In high speed transmission applications, the connectors here are frequently configured as what are referred to as small form pluggable connectors, SFP connectors for short. There are different variant embodiments in this connection, for example what are referred to as SFP connectors, SFP+ connectors, or CXP QSFP connectors. These connectors have special connector housings, as can be gathered, for example, from international patent disclosures WO 2011 072 869 A1 (corresponding to U.S. Pat. No. 8,444,430) or WO 2011 089 003 A1 (corresponding to U.S. Pat. No. 8,556,646).
The interior of such connector housings has a printed circuit board or board sometimes with integrated electronics. The respective data cable is to be connected to the board on a rear side of the connector. The individual insulated wires of the data cable are soldered here to the board. At the opposite end of the board, the board typically forms a plug-in tongue with connection contacts, said plug-in tongue being plugged into a mating connector. Boards of this type are also referred to as paddle cards.
In the case of data connections of this type having a very high transmission frequency, reliable shielding is of crucial importance. The shielding of the individual data lines, i.e. of the individual pairs of insulated wires, has to be reliably connected here to the respective connector, in particular to the board.
A “ground wire” which is electrically connected to the shielding and via which ultimately the electrical contacting of the shielding with a ground connection of the board takes place is frequently arranged in a respective data line. One ground wire is customarily provided per pair of insulated wires, which are typically stranded together in pairs in the manner of a twisted pair, and a plurality of pairs of insulated wires is connected. Such a data line with a ground wire can be gathered, for example, from published European patent application EP 21 12 669 A2 (corresponding to U.S. patent publication No. 2009/0260847). However, the contacting of the ground wire is associated with complexity in terms of production, and also, because of the individual contacting of the ground wires of the various data lines, a certain construction space is required which is troublesome in the case of the comparatively small connectors. The ground wire also has to be aligned in order to guide it to the desired connection position.